Method for screen assembly



Oct. 26, 1965 F. w. ROWBOTTAM METHOD FOR SCREEN ASSEMBLY 2 Sheets-Sheet1 Filed Feb. 12, 1962 INVENTORS. r f 1W7.- M RQWBOTTA BY Mun-x A4 AAKMEY A GENT METHOD FOR SCREEN ASSEMBLY Filed Feb. 12, 1962 2Sheets-Sheet 2 INVENTORS. k c s M Rom/607741? WALTER fi fi/A/WEV AGE/w"United States Patent 3,214,314 METHOD FOR SCREEN ASSEMBLY Francis W.Rowbottam, Palos Verdes, Calif. (1911 W. 139th St, Garden-a, Calif.)Filed Feb. 12, 1962, Ser. No. 172,499 2 Claims. (Cl. 156160) Thisinvention relates to method and apparatus for screen assembly and isparticularly concerned with automated installation of screening upon aframe, it being a general object of this invention to automaticallyassemble screening upon frames that vary in size and in proportion.

Screening is ordinarily installed by hand upon frames that are designedto maintain said screening in a taut planar condition. In order toproperly apply screening to frames a technique must be developed wherebyappropriate tautness is achieved, but without distorting the frame. Theproblem arises in the frailty of the frames which are of lightconstruction and which have a rabbet groove for the reception of aretaining strip or filler that wedges the marginal portion of thescreening in said rabbet groove. The filler strip is usually appliedwith an instrument adapted to apply pressure with experiencedmanipulation, with the screening beneath the filler strip so as to bepressed into the rabbet groove. In any case, the careful manualapplication of the filler strip to retain the screen in the rabbetgrooves is time-consuming, and the output of a skilled workman is ratherlimited, the installation of said screening being slow and tedious.

An object of this invention is to receive random sized frames and toinstall screening thereon without resort to manual labor.

Another object of this invention is to provide an apparatus for thepurpose set forth above and which operates continuously and withoutinterruption. That is, the method and apparatus herein disclosed doesnot intermittently start and stop, and on the contrary it operates at auniform and continuous rate of speed.

It is an object of this invention to provide a method of assemblingscreening upon a frame whereby tedious manual operations are eliminatedand whereby said screening is anchored by means of a single easilyperformed step, a step that is readily performed by a ma chine orapparatus, when circumstances require.

It is still another object of this invention to provide a unique methodwhereby screening is permanently attached to a supporting frame, withoutthe usual tedious time-consuming manipulations that are ordinarilyresorted to. With the present invention, two steps characterize themethod, namely, (1) to tension the screen in place over a frame, and (2)to fuse the screening to the frame, the only requirement being thatfusible materials be involved whereby the screening is fastened to theframe.

The various objects and features of this invention will be fullyunderstood from the following detailed description of the typicalpreferred form and application thereof, through which descriptionreference is made to the accompanying drawings, in which:

FIG. 1 is a perspective view of a typical screen unit.

FIG. 2 is an enlarged sectional view taken as indicated by line 22 onFIG. 1, and showing the characteristic features of the present inventionas initially prepared.

FIG. 3 is a view similar to FIG. 2, and shows the installation thereonof the screening.

FIG. 4 is a schematic plan view of the apparatus provided to carry outthe steps of the present invention.

FIGS. 5, 6 and 7 are enlarged sectional views taken substantially asindicated by lines 55, 6--6, and 77 on FIG. 4.

For a proper understanding of this invention it is neces- 3,214,314Patented Oct. 26, 1965 sary to have in mind the nature of the frame 10involved and of the finished screen 11 that is produced. The frame 10 isa light weight structure made up of right angularly related rails 12,adjoining in abutted relationship at mitered corners 13. The rails 12are tubular and formed of sheet metal, and a right angle fitting (notshown) enters abutting rails to join them at said corners, a frictionfit being, provided. In order for the rail 12 to receive and retainscreening S a rabbet groove 15 is provided at the inner marginal portionof the rail, and in the construction of the groove the sheet metal isoverlapped and connected. In making this connection at groove 15, theouter plane of metal is turned to form a complete two-sided channel witha bottom, and the edge plane of metal is turned over the marginalportion of the metal forming the outer side of the channel. In any case,the overlapping of metal occurs at one side wall of the channel, at theinner side thereof, and the edge of the exposed overlap terminates at adownwardly faced step spaced from the bottom of the channel.

With the foregoing usual practice in mind, concerning frameconstruction, it is usual to force screening S into the channel formingthe rabbet groove 15 using a strip or filler, this being a manualoperation as hereinabove described. However, with the present inventiona strip or filler is not applied as a mechanical key to wedge thescreening S in the groove 15. On the contrary, a fusible material F isinitially installed in the groove 15, to occupy the same and to beconnected by fusion to the screening S. In the preferred form of thisinvention the fusible material F is vinyl, a plastic material that isreadily fused to the material forming the screening S. It is preferred,also, that the screening be made of vinyl, the same plastic material. itis to be understood, however, that a wide range of equivalent materialscan be utilized and that it is possible to fuse to or around metalscreening S, or other dissimilar materials, using the fusible materialF. This invention is characterized by the connection of screening S ontoa part of the frame 10, preferably a fusible strip of material F carriedby the frame. Although said fusion can be carried out in various ways,it is preferred to employ the direct application of heat, it beingunderstood that chemical action, for example, can be applied, if sodesired.

In accordance with the invention, a frame 10 is acquired in assembledcondition, having four rails 12 suitably joined and with a body offusible material F, initially lodged in the rabbet groove 15. Of course,the groove 15 opens in one direction exposing the material F at the faceplane of the frame 10, and thus the screening S contacts the saidfusible material F when brought into fiat engagement with said faceplane of the frame. Said material F is of tubular cross-section so as tobe compressed into the groove 15, it has a lip 16 to engage under theedge of metal exposed in the channel groove, and it has a projecting rib17 to be fused into the mesh of the screening S. As shown, the rib 17projects from the said face plane of the frame 11.

The method of this invention is practiced by: firstly stretchingscreening S over the frame 10, and secondly engaging the screening withsaid fusible material and fusing the same together. Thirdly, the excessscreening S outside of the joint made by fusion is eliminated bytrimming with a sharp cutting instrument.

The first step of the method involves stretching of the screening S in amanner to maintain a flat plane thereof, and this requires theengagement of opposite marginal edges of the screening and pulling thesame taut. It is usually sufficient to tension the screen from twoopposite edges, and in extreme circumstances, as with large screens 11,it is feasible to tension the screen from all four edges. In any case,it is required that the screening S be at least 3 coextensive with theframe 10, and by this it is meant that the margins of the screening 3overlie the fusible material F to which it is to be attached.

The second step of the method involves bringing of the screening S intoengagement with the fusible material F and fusing the same together. Inpractice, heat is the preferred means of causing the desired fusion, andthere are various ways and means suitable for the application of saidheat. For example, heat lamps, electronic heat generation or heatapplicating irons are all feasible. Since the least complicated is thelatter, the ironing means is preferable and is shown in the form ofinvention illustrated. Thus, a heated iron element 18 is placed incontact with the screening S at the fusible material F, and one or both(5 and/or F) are fused into engagement. Said ironing element 18 can bemanipulated or mechanically controlled to press against the parts to bejoined and to contact, wipe or roll over them, as circumstances require.

As a result of the two simple steps above described, and as they areapplied to the particular elements involved, a piece of screening S isreadily applied to and fastened securely on a frame It), with thescreening tensioned but not in excess, all without undue strain on theframe. Further, the installation of the screening is done in onemovement of attachment, said heat being applicable to the entire screenat one short time interval, for example, during but a fraction of asecond.

Apparatus is provided to carry out the method hereinabove disclosed,whereby a continuous mechanized production of screens 11 is obtained. Asshown in the drawings, the apparatus involves, generally, a frame feederA, a screening feeder B, a conveyor C, a fusing means D, a trimmingmeans E, and cutting means K. The means A through K are supported on abase indicated in the drawings shown as 20 and interrelated as laterdescribed. In order to carry out the method involved; the means A-supplies random sized and/or various shaped frames, the means B suppliesscreening S in a taut and continuous manner, the conveyor C operates tomove the frames 10 with screening S thereon, the fusing means D operatesto attach the screening S to the frames 10, the trimming means Eoperates to dress the final product in the form of a screen, and thecutting means K operates to sever the screens from the supply ofscreening.

The frame feeder A that supplies all sizes and forms of frames 10 is notlimited to any particular dimension of frame and it is such as todeliver any size frame 10, within limits and one at a time. The feeder Ainvolves a conveyer supported stack or supply 21 of frames 10, and itinvolves right angularly related fences 22 and 23 to place a givencorner of each of the frames being handled. The fences 22 and 23 arespaced above the supporting surface of a table 24-, so as to permitdelivery of one frame at a time, in a lateral direction parallel to oneof the said fences. In order to deliver the frames 10 there is a drivemotor 25 that operates chains 26, and a cleat 27 extends between thechains 26 to engage and move each successive lowermost frame 10. The twochains 26 move together, between spaced shafts, to maintain alignment ofthe cleat 27. The motor 25 operates through a slip clutch 28 so that theframe being delivered can be held in pressured engagement with a stoprail 29. Then, as soon as each frame is removed from said pressuredengagement between cleat 27 and stop rail 29, the chains are free todeliver the next successive frame 10.

The screening feeder B that continuously supplies taut screening 5involves two pairs of screen driving rollers -31 and 32-33. The rollers30-31 receive screening S therebetween from a roll R thereof, with meanssuch as spring means to pressure the rollers into driving engagementwith the screening S. The rollers 32-33 are spaced from the rollers39-31 a distance substantially greater than the largest screen dimensionto be handled, with a spring means to pressure the rollers into drivingengagement with the screen S and frame therebetween. In carrying out theinvention, the rollers 32-33 are driven somewhat faster than the rollers30-31, whereby the screening S is pulled taut between the said rollers.

In accordance with the invention, the frame feeder A delivers frames It)intermittently and one at a time in a direction transversely of thescreening feeder B and intermediate the two pairs of driving rollers30-31 and 32-33. As shown, the feeder A is at one side of the feeder Band with the stop rail 29 at the opposite side of the feeder B. Thus,the frames 10 are stopped in pressured engagement with the rail 29 atthe said opposite side of the feeder B.

The conveyer C that moves the frames 10 with screening thereon isincorporated in the lowermost rollers 30 and 32, there being a belt 35extending over these rollers. The belt 35 is rather narrow and locatedadjacent the stop rail 29. The top section of belt 35 is in a plane toslidably receive and then support the frames 10 delivered by the feederA, and it operates continuously to deliver frames with screening Ssuperimposed thereon, issuing from the rollers 32-33.

As clearly shown, the roll R of screening S is sufficiently Wide toinclude all screen frames 10 to be handled, that is, to overlie thematerial F of said frames.

The fusing means D that attaches the screening S to the frames 10 isincorporated in the uppermost roller 33, and the roller 33 is thereforea heated roller that is thermostatically controlled. Thus, as the frameslt) pass between the rollers 32-33 pressure is applied and heat isabsorbed into the metal frames 10 from the roller 33. As a result ofthis heat transfer there is the presence of heat to fuse the material Finto the screening S, or vice versa, as the case may be. Thus, everypart of the frames 10 passing between the rollers 32-33 is affected, sothat both transverse and longitudinal joinders are made.

The trimming means E that dresses the final product, screens 11, isadapted to sever excess marginal portions of screening from the frames19. Although the cutter means K operates within the functions of thetrimming means E, said means B will be first described. Note that twopairs of parallel and right angularly related margins of screening Smust be trimmed from each of the rectangular frames 10 handled by theapparatus. In practice, this trimming is done just outside of the lineof joinder, as clearly indicated in FIG. 3 of the drawings. As shown inFIG. 4 there is a pair of right angularly related shafts 36 and 36carrying cutters 37-37a and 3838t1, respectively. The cutter 3'7 followsthe rollers 32-33 and is substantially aligned with the stop rail 29, soas to press onto the frame It at the line indicated in FIG. 3. Thecutter 37a is slidably carried on shaft 35 and is positioned therealongby means of a cam-shaped feeler 39 that engages the edge of frame 16opposite and parallel with the edge guided by stop rail 29. A springmeans 40 yieldingly urges the feeler 39 into said engagement, wherebythe cutter 37a is aligned so as to press onto the frame 10 at the lineindicated in FIG. 3.

A continuation of the conveyor C follows the cutters 37 and 37a, therebeing a pair of driving guide rollers 4-1-42 to receive the screens andmove them forwardly through the cutter means K later described. Saidcontinuation of the conveyor C comprises spaced rolls 43 and 44 with abelt operating thereon to support and move the frames with screening. Inorder to establish transverse right angular movement of screens, atransversely moving stop 50 is provided and which comprises a pair oftransversely spaced rolls 48 and 49 with a drive belt 51 therebetween.The belt 51 can be provided with cleats, or the like, for suflicientfrictional engagement with the forwardmost rail of the advancing frame10, to move the screen frames laterally. In order to trim the remainingmargins of the screening S, drive rollers 52-53 are provided to receivethe laterally moved frames with the screening thereon. The rollers 52-53are placed at the side of the conveyor C opposite the stop rail 29 andparallel thereto.

The cutter 38 follows the rollers 52-53 and is substantially alignedwith the stop 50 that moves, so as to press onto the frames at the lineindicated in FIG. 3. The cutter 38a is slidably carried on shaft 36 andis positioned therealong by means of a cam-shaped feeler 54 that engagesthe edge of the frames 10 opposite and parallel to the stop 50. A springmeans 55 yieldingly urges the feeler 54 into engagement with the frame,whereby the cutter 38a is aligned so as to press onto the frame 10 atthe line indicated in FIG. 3.

The cutting means K that severs the frames 10 with screening S thereonfrom the supply roll R is preferably a shears located intermediate theright angularly related trimming functions of the previously describedmeans E. As shown, the cutting means K follows the cutters 37-37a justahead of the continuation of the conveyor C, and it is adapted to slicethrough the screening S following passage therethrough of the frames 10.An electrical switch 56 is indicated and which electrically controlsoperation of the cutter K. Thus, each time a frame 10 passes the cuttermeans K a slicing operation is performed, thereby severing the frames 10from the supply roll R. The frames 10 with screening S thereon are thenfree to be moved laterally for the remainder of the trimming operation.

From the foregoing it will be seen that the method herein disclosed canbe performed manually or by an apparatus such as is shown. Thefeasibility of the method is inherent in either case and is such as toeliminate the tedious manual application of a wedging strip into therabbet groove. It is clear that this invention deviates from the usualpractice by employing material, fusible material, initially installed inthe rails, and said installation of fusible material is readilyperformed by automated processes, not shown. It will be apparent thatsuitable drive means can be provided to rotate the chains, rolls,rollers, and various gearing hereinabove described, and in a synchronousmanner whereby the apparatus operates in unison. As a result, randomsized frames, rectangular in form, are handled entirely withoutmanipulation during the process involved, namely, the installation ofscreening S upon frames 10 and including the removal of excess marginalportions of screening S.

Having described only a typical preferred form and application of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself anymodifications or variations that may appear to those skilled in the artand fall within the scope of the following claims.

Having described my invention, I claim:

1. A method of making screens, that includes:

providing a frame having contiguous rails, one face of said rails havinga groove;

applying a fusible strip into each of said grooves;

holding screening material tensioned in a plane parallel with the planeof said one face of said rails, the tensioning force being applied frompoints outside the margins of said frame;

engaging said screening material with said fusible strip material whilesaid screening material. is so tensioned; fusing said screening materialto said fusible strip while said screening is so tensioned;

and thereafter trimming said screening material to the marginal portionsof said groove.

2. The method of claim 1 wherein heat is applied to fuse said strip withsaid screening.

References Cited by the Examiner UNITED STATES PATENTS 1,198,134 9/ 16Kercher 29447 1,714,468 5/29 Espenschied -109 2,316,526 4/43 McDonald371 2,342,025 2/ 44 Watter 29-447 2,343,037 2/44 Adelman 161-442,471,612 5/49 Freeman 156-273 2,514,920 7/50 Wright 160-371 2,638,1315/53 Rohs 140-409 2,649,392 8/53 Marshall 156-306 2,832,407 4/58 Tracy160-371 2,886,481 5/59 Swan 160-354 3,005,483 10/61 Middents et al156583 3,107,991 10/63 Taussig 160-371 EARL M. BERGERT, PrimaryExaminer.

NED BERGER, Examiner.

1. A METHOD OF MAKING SCREENS, THAT INCLUDES: PROVIDING A FRAME HAVINGCONTIGUOUS RAILS, ONE FACE OF SAID RAILS HAVING A GROOVE; APPLYING AFUSIBLE STRIP INTO EACH OF SAID GROOVES; HOLDING SCREENING MATERIALTENSIONED IN A PLANE PARALLEL WITH THE PLANE OF SAID ONE FACE OF SAIDRAILS, THE TENSIONING FORCE BEING APPLIED FROM POINTS OUTSIDE THEMARGINS OF SAID FRAME; ENGAGING SAID SCREENING MATERIAL WITH SAIDFUSIBLE STRIP MATERIAL WHILE SAID SCREENING MATERIAL IS SO TENSIONED;FUSING SAID SCREENING MATERIAL TO SAID FUSIBLE STRIP WHILE SAIDSCREENING IS SO TENSIONED; AND THEREAFTER TRIMMING SAID SCREENINGMATERIAL TO THE MARGINAL PORTIONS OF SAID GROOVE.